Ming-dynasty scholar Pan Zhicong's Shufa ligou (Calligraphy Off the Hook) emphasizes the dialectical relationship between qufa (acquire the rules) and lifa (desert the rules). Pan describes a caligrapher's three-step process from degou (on the hook), to tungou (master the hook), and to ligou (off the hook), which demonstrates the three phases of his artistic accomplishment: from adopt, to master, and to desert the rules and finally achieve the highest form of artistic freedom. This is closely related to the three stages of Zen Buddhist cultivation.